In medical imaging, such as digital radiography, one significant goal is minimize patient exposure to x-rays. As such, medical imaging X-ray light source typically includes movable (adjustable) “blades” that limit an area of exposure to the general vicinity of the section of human anatomy of interest, the “Region Of Interest” (ROI). For example, a relatively small exposure area might be used to image a human hand. There can be four blades (e.g. right, left, top, and bottom) that can range from fully open (maximum exposure area), to partially closed, causing a relatively small rectangular exposure area. Imaging equipment generally provides a sensor or detector that records the maximum possible exposure area and generates a digital image. The digital image contains exposed and unexposed regions. Further image processing of the entire detector area can be wasteful, since there is no useful diagnostic information in unexposed regions.
What is needed, therefore, is a system and method to identify an ROI in an x-ray image and to limit image processing to only exposed regions.